Investigating the Impact of Plant Phytoremediation on Indoor Air Quality in Work Environments: A Meta-Analysis

摘要

Studies of indoor air quality have prompted serious concerns of occupant's health and human well-being, which might not be fully achieved solely by current ventilation strategies. Environmental exposures to indoor contaminants such as volatile organic compounds (VOCs), and Carbon Dioxide emissions (CO2) levels remain problematic issues that might not be fully addressed through increased levels of ventilation rate only. Living media where plants are able to remove indoor contaminants can provide an effective passive strategy that impact occupant's health, well-being, as well as building's ventilation system efficacy. Despite many studies on horticultural biotechnologies for improving indoor air quality in laboratory settings, active botanical biofilters or functional green walls seem to perform differently in actual indoor spaces rather than being assessed in closed experimental chambers. By introducing the idea of incorporating active botanical green wall systems as an air filtration strategy into double skin facades, a dual benefit might be achieved to improve indoor air quality and the building's energy saving potential by improving thermal performance of the building's envelope. This paper aims at evaluating previous results of biofiltration, botanical air filters, and potted plants by comparing their removal efficiencies to their air chamber volumes based on a meta-analysis of published results. Results are presented through specific defined metrics in which independent variables in the form of, plant species, leaf areas, time, air volume, and chamber geometry are computed to present spatial and technical influences of different experimental conditions in reducing indoor air contaminants. The paper concludes that plants show higher removal efficiencies when placed in enclosed spaces with higher ratio of leave areas to chamber volumes which also increases the rate of filtration. Although plants' latent heat might improve the envelope thermal insulation, air volume and stratification are more significant variables at improving the envelope thermal properties. Further studies are needed to test the impact of enclosed botanical biofilters in field studies and under different climatic and building types to determine the suitability and optimization potential of this strategy for the design of high-performance envelopes.